Field of the Invention
The present invention relates to an imprint method, imprint apparatus, and article manufacturing method.
Description of the Related Art
An imprint method including three modes for a peripheral shot region including the outer periphery of a substrate is described in Japanese Patent Laid-Open No. 2007-019466. In the first mode, no imprint process is performed on the peripheral shot region. In the second mode, an imprint process is performed on the peripheral shot region by using a mold to be used to imprint an inner shot region not including the outer periphery of the substrate. In the third mode, the imprint process is performed on the peripheral shot region by using a mold different from the mold to be used to imprint the inner shot region, and corresponding to the shape of the peripheral shot region.
The shot region normally includes a plurality of chip areas. In the first mode, the yield is low because no chip pattern is formed in the peripheral shot region. In the second mode, chip patterns are effectively transferred to a chip area (valid chip area) positioned in the peripheral shot region and not including the outer periphery of the substrate, and only chip patterns transferred to a chip area (invalid chip area) including the outer periphery of the substrate are invalidated. Accordingly, the second mode is superior to the first mode in yield. In the second mode, the peripheral shot region is imprinted by using the mold to be used to imprint the inner shot region, so the entire peripheral shot region is presumably coated with a resin (the resin is presumably dispensed on the entire peripheral shot region). When performing the imprint process on the peripheral shot region in this state, the resin dispensed on the invalid chip area positioned in the periphery of the substrate may be pushed outside the substrate from between the mold and substrate. Since an imprint apparatus is an apparatus for transferring micropatterns onto a substrate, the reliability decreases if the pushed resin adheres to the mold or a substrate holding unit. Especially when the resin adheres to the mold, a pattern defect is highly likely to occur.
In the third mode, the imprint process is performed on the peripheral shot region by using a mold having a shape corresponding to the peripheral shot region, because if the mold for the inner shot region is used, the mold may be damaged by stress concentration or the like. The imprint process for the peripheral region in the third mode is performed to improve the uniformity of the whole substrate in processes such as dry etching and ion implantation. In addition, this imprint process is not separately performed for the valid chip area and invalid chip area. Also, if the imprint process for the peripheral region is performed by coating the entire peripheral shot region with a resin, the resin may be pushed outside the substrate from between the mold and substrate and cause a pattern defect as in the second mode. Furthermore, in the third mode, when the shape of the peripheral shot region is changed in accordance with, for example, the shot layout of the inner shot region, it is necessary to prepare a new peripheral shot region mold corresponding to the changed shape. Therefore, the third mode requires a high cost in order to prepare a number of peripheral shot region molds.